JPS6361641B2 - - Google Patents
Info
- Publication number
- JPS6361641B2 JPS6361641B2 JP59119474A JP11947484A JPS6361641B2 JP S6361641 B2 JPS6361641 B2 JP S6361641B2 JP 59119474 A JP59119474 A JP 59119474A JP 11947484 A JP11947484 A JP 11947484A JP S6361641 B2 JPS6361641 B2 JP S6361641B2
- Authority
- JP
- Japan
- Prior art keywords
- lens
- lens group
- zoom
- wide
- angle end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000014509 gene expression Effects 0.000 claims description 13
- 230000004075 alteration Effects 0.000 description 17
- 238000010586 diagram Methods 0.000 description 11
- 230000003287 optical effect Effects 0.000 description 6
- 230000008859 change Effects 0.000 description 4
- 230000009471 action Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000003384 imaging method Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/142—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having two groups only
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Description
本発明は小型のズームレンズに関し、特にレン
ズシヤツターカメラ、ビデオカメラ等に有効なレ
ンズ全長(第1レンズ面から像面までの距離)の
短い小型のズームレンズに関するものである。
近年レンズシヤツターカメラ、ビデオカメラ等
の小型化に伴いレンズ全長の短いズームレンズが
要求されている。又レンズシヤツターカメラ等の
レンズ交換を行なわないカメラ分野でもズームレ
ンズの装着が要求されており、従来用いられてい
た単焦点レンズと同程度の長さの小型のズームレ
ンズが要求されている。
本出願人は特開昭57−201213号公報において、
第1図に示すように正の屈折力の第1レンズ群
と負の屈折力の第2レンズ群の2つのレンズ群
より構成し、両レンズ群の間隔を変化させて変倍
を行う小型の2群ズームレンズを提案した。
同提案では物体側より順に正と負の屈折力のレ
ンズ群構成とすることによりバツクフオーカスの
短い機構上簡単な構成の小型のズームレンズを達
成している。
又特開昭58−184916号公報では物体側より順に
正、正、そして負の屈折力の第1、第2、第3レ
ンズ群の3つのレンズ群より構成し前記3つのレ
ンズ群を移動させて変倍を行つた3群ズームレン
ズが提案されている。
しかしながら前述の2群ズームレンズでは変倍
による移動するレンズ群が2群の為に比較的レン
ズ群の移動を多くしなければ所定の変倍比を得る
ことが困難であり又3群ズームレンズは変倍の為
に3つのレンズ群が移動させているので機構的に
複雑になる傾向がある。
又双方のズームレンズはいずれも変倍により絞
りも移動させている為に移動機構が複雑化する傾
向があつた。
本発明は所定の変倍比が容易に得られしかも機
構的に簡単なレンズ全長の短い小型のズームレン
ズの提供を目的とする。本発明の更なる目的は変
倍比1.5〜2.0程度のレンズシヤツターカメラに適
した小型のズームレンズの提供にある。
本発明の目的を達成する為の小型のズームレン
ズの主たる特徴は物体側より順に正、正そして負
の屈折力の第1、第2、第3レンズ群の3つのレ
ンズ群を有し、前記第2レンズ群を固定させ、前
記第1レンズ群と前記第3レンズ群を物体側へ移
動させることにより広角端よる望遠端のズーム位
置への変倍を行う際、前記第2レンズ群と前記第
3レンズ群の結像作用が共に増倍となるように各
レンズ群を構成したことである。
次に第2図に本発明の一実施例の光学配置の概
略図を示す。同図において、,,は各々第
1、第2、第3レンズ群であり矢印は変倍の際の
移動状態を示す。
前述の如く、本発明においては変倍を3つのレ
ンズ群のうち第1、第3レンズ群の2つのレンズ
群を移動させ、絞りが含まれる場合の多い第2レ
ンズ群を固定させて機構上の簡素化を図つてい
る。
又広角端より望遠端のズーム位置への変倍に際
して、第2レンズ群の横倍率β2及び第3レンズ群
の横倍率β3が共に連続的に増倍となるように構成
して変倍を効率的に行つている。
更に本発明において好ましくは第2レンズ群と
第3レンズ群の合成屈折率を負とし、しかも負の
屈折力が変倍に際して徐々に強くなるようなレン
ズ構成とすることが良く、これによりレンズ群の
少ない移動量で所定の変倍比を効率よく達成して
いる。
本発明の目的とする小型のズームレンズは、以
上の諸条件を満足することにより達成されるもの
であるが更に好ましくは前述の諸条件につき、次
の如く設定するのが良い。
前述の結像作用において広角端と望遠端の横倍
率をそれぞれ第2レンズ群をβ2W,β2T、第3レン
ズ群をβ3W,β3Tとすると
1.0<β2T/β2W<1.5 ……(1)
1.0<β3T/β3W<1.7 ……(2)
の範囲内に設定することである。これにより、3
つのレンズ群の変倍による収差変動を少なくしつ
つバランス良く所定の変倍比を得ることができ
る。
条件式(1),(2)の上限を越えると、変倍比が大き
くなりすぎ、各レンズ群の屈折力が過大、もしく
はレンズ群の移動量が過大となり変倍による収差
変動を小さくすのが困難となる。
又条件式(1),(2)の下限を越えてズームレンズを
構成することは光学的に非常に難しくなる。特に
増倍比が小さすぎて、所定の変倍比を得るのが2
つのレンズ群の移動では難しくなつてくる。
更に本発明においては前記条件式(1),(2)下で第
2レンズ群と第3レンズ群の、広角端と望遠端の
ズーム位置における合成屈折力を各々23W,23T
とするとき
1.2<23T/23W<4.0 ……(3)
の範囲内に設定するのが好ましい。このような屈
折力配置とすることにより第3レンズ群の移動量
を、あまり増加させずに所定の変倍比を容易に得
ることができる。
なぜなら第2レンズ群と、第3レンズ群の焦点
距離を各々f2,f3、第2レンズ群と第3レンズ群
の主点間隔をe2、第2レンズ群と第3レンズ群の
合成屈折力を23とすると
23=1/f2+1/f3−e2/f2f3 ……(a)
と表わすことができる。ここで上式(a)において
1/f2>0,1/f3<0であるため1/f2+1/f3<0
となる
ように各レンズ群の焦点距離を設定し、広角端か
ら望遠端のズーム位置への変倍に際してe2を小さ
く、すなわち第3レンズ群を物体側へ移動させる
ことにより序々に屈折力23を負の方向に強くす
ることができるからである。このため望遠端のズ
ーム位置での屈折力23を負の方向で最大とする
ことができ、この結果第3レンズ群を僅かに移動
させることによつて容易に高変倍比を得ることが
できる。
以上説明した如く、各レンズ群の構成を選定す
ることにより本発明の目的は良好に達成されるが
全変倍範囲にわたり更に良好なる収差補正を達成
し、ズームレンズの小型化を図るには次の諸条件
を満足するのが好ましい。
前記第1、第3レンズ群の焦点距離を各々f1,
f3、広角端のズーム位置における全系の焦点距離
をfW、広角端のズーム位置での前記第1レンズ群
と前記第2レンズ群の主点間隔をe12W、望遠端の
ズーム位置での前記第2レンズ群と前記第3レン
ズ群との主点間隔をe23Tとするとき、
0.3fW<f1<5fW ……(4)
−2.5fW<f3<−0.5fW ……(5)
e12W>−0.5fW ……(6)
e23T>−0.4fW ……(7)
なる条件を満足することである。
条件式(4)は第1レンズ群の屈折力に関するもの
で、下限値を越すと変倍比を得るために特に望遠
端で第2レンズ群と第3レンズ群の屈折力が負の
大きな値となるため、ペツツバール和が負の方向
に増大し像面湾曲がオーバーとなる。逆に上限値
を越えると第1レンズ群には変倍の寄与が小さく
なるのみならず、第3レンズ群の横倍率β3を小さ
くしなければならなく第3レンズ群の負の屈折力
を小さくしなければならない。この結果第3レン
ズ群の移動量が大きくなり、レンズ全長が長くな
り適当でない。
条件式(5)は、第3レンズ群の屈折力に関するも
ので上限値を越えると負の屈折力が大となりペツ
ツバール和が負の方向に増すため像面湾曲が正の
方向に増大し、又、下限値を越すと第2レンズ群
との合成屈折力が正の方向に近づくので上述の如
く、第3レンズ群を僅か動かすことによる高変倍
比が得られず、大きな移動量が必要となる。又下
限を越えて合成屈折力を負の方向に保ち、所定の
変倍比を得ようとすると、前記(a)式により、第2
レンズ群の正の屈折力が弱くなり、第2レンズ群
と第3レンズ群の主点間隔e2を小さくしていく必
要があり、第3レンズの移動空間が得られず、適
当でない。
条件式(6),(7)は各レンズ群との間隔を適切に設
定レンズ全長の短縮化を図るためであり、条件式
(6),(7)の範囲を逸脱すると、各々広角端及び望遠
端でのレンズ群間隔が狭くなりすぎレンズ群どお
しが干渉してくるのでレンズ構成上好ましくな
い。
尚本発明においては、変倍中固定の第2レンズ
群の焦点距離f2を
0.5fW<f2<6fW ……(8)
の如く設定するのが第1レンズ群と第3レンズ群
の移動による変倍効果を助長させ、しかも変倍に
おいて画面全体の収差を良好に補正するのに好ま
しい。
条件式(8)の上限値を越えると、第2レンズ群の
屈折力が弱くなり、所定の変倍比を得ようとする
と、前記(a)式より、第2レンズ群、第3レンズ群
の主点間隔e2を大きくとる必要があり、また第3
レンズ群の負の屈折力も弱くなり移動量が大きく
なる。また下限値を越えると第2レンズ群の屈折
力が強くなり、第3レンズ群の負の屈折力が過大
となり、また第2レンズ群と第3レンズ群の主点
間隔が小さくなり移動空間がなくなり適当でな
い。
本発明のように変倍により第3レンズ群が移動
するズームレンズにおいては第3レンズ群を像面
側に凸面を向けたメニスカス状の負の屈折力のレ
ンズより構成するのが全変倍範囲にわたり画面全
体の像面特性を良好に補正するのに好ましい。
又本発明の如く変倍により第1、第3レンズ群
が移動するズームレンズにおいて変倍による収差
変動を少なくし、画面全体にわたり諸収差を良好
に補正する為には第1レンズ群と第3レンズ群の
物体側の第1レンズ面の曲率半径を各々R11,
R31とするとき
0.5fW<R11<fW ……(9)
−0.6fW<R31<−0.2fW ……(10)
なる条件を満足させることが好ましい。条件式
(9),(10)は変倍による球面収差及び画面全体の像面
湾曲を良好に補正する為であり条件式(9)の上限
値、条件式(10)の下限値を越えると球面収差は補正
過剰となり又広角側での像面湾曲が負の方向に増
大してくる。条件式9の下限値、条件式(10)の上限
値を越えると球面収差が補正不足となり又像面湾
曲が正の方向に増大してくるので好ましくない。
尚本発明においては第3レンズ群の物体側のレ
ンズ面を非球面とするのがより良好なる収差補正
を達成し高性能な光学性能を得るのに好ましい。
本発明において焦点合わせはレンズ系全体を繰
り出して行うのが良いが第1レンズ群若しくは第
2レンズ群を繰り出しても若しくは第3レンズ群
を繰り込むことによつても良く又第1レンズ群と
第2レンズ群を一体的に繰り出して行つても良
い。
以上のように本発明によれば機構的に簡単でし
かも変倍効率の良い小型のズームレンズを達成す
ることができる。
次に本発明の数値実施例を示す。数値実施例に
おいてRiは物体側より順に第i番目のレンズ面の
曲率半径、Diは物体側より順に第i番目のレンズ
厚及び空気間隔、Niとνiは夫々物体側より順に第
i番目のレンズのガラスの屈折率とアツペ数であ
る。
非球面形状は光軸方向にX軸、光軸と垂直な方
向にY軸、光の進行方向を正とし、レンズの頂点
とX軸の交点を原点に採り、Rをレンズ面の近軸
曲率半径、a1,a2,a3,a4,a5,b1,b2,b3,b4
を非球面係数とするとき
なる式で表わされるものである。
又例えば「D―03」の表示は「10-3」を意味す
る。
The present invention relates to a compact zoom lens, and more particularly to a compact zoom lens with a short overall lens length (distance from the first lens surface to the image plane) that is effective for lens shutter cameras, video cameras, and the like. In recent years, with the miniaturization of lens shutter cameras, video cameras, etc., there has been a demand for zoom lenses with short overall lens lengths. Also, in the field of cameras such as lens-shutter cameras in which lenses are not replaced, there is a demand for a zoom lens, and there is a demand for a compact zoom lens with a length comparable to that of conventional single-focal-length lenses. In Japanese Patent Application Laid-Open No. 57-201213, the applicant
As shown in Figure 1, it is a compact lens that consists of two lens groups, the first lens group with positive refractive power and the second lens group with negative refractive power, and zooms by changing the distance between both lens groups. We proposed a two-group zoom lens. In this proposal, by configuring lens groups with positive and negative refractive powers in order from the object side, a compact zoom lens with a short back focus and a mechanically simple configuration was achieved. Furthermore, in Japanese Patent Application Laid-Open No. 58-184916, it is composed of three lens groups, first, second, and third lens groups having positive, positive, and negative refractive powers in order from the object side, and the three lens groups are moved. A three-group zoom lens that performs magnification change has been proposed. However, with the aforementioned two-group zoom lens, since there are only two lens groups that move during zooming, it is difficult to obtain a predetermined zoom ratio without moving the lens groups relatively often. Since three lens groups are moved to change the magnification, they tend to be mechanically complex. Furthermore, since both zoom lenses also move the aperture when changing the magnification, the movement mechanism tends to become complicated. SUMMARY OF THE INVENTION An object of the present invention is to provide a compact zoom lens that can easily obtain a predetermined variable power ratio, is mechanically simple, and has a short overall lens length. A further object of the present invention is to provide a compact zoom lens suitable for a lens shutter camera with a variable magnification ratio of about 1.5 to 2.0. The main feature of the compact zoom lens for achieving the object of the present invention is that it has three lens groups, first, second, and third lens groups having positive, positive, and negative refractive powers in order from the object side. When changing the magnification from the wide-angle end to the telephoto end zoom position by fixing the second lens group and moving the first lens group and the third lens group toward the object side, the second lens group and the third lens group move toward the object side. Each lens group is configured so that the imaging action of the third lens group is multiplication. Next, FIG. 2 shows a schematic diagram of an optical arrangement according to an embodiment of the present invention. In the figure, , , are the first, second, and third lens groups, respectively, and the arrows indicate the state of movement during zooming. As mentioned above, in the present invention, zooming is achieved mechanically by moving two of the three lens groups, the first and third lens groups, and fixing the second lens group, which often includes an aperture. We are trying to simplify the process. In addition, when changing the zoom position from the wide-angle end to the telephoto end, the lateral magnification β 2 of the second lens group and the lateral magnification β 3 of the third lens group are both continuously multiplied. are being carried out efficiently. Furthermore, in the present invention, it is preferable that the combined refractive index of the second lens group and the third lens group is negative, and the lens structure is such that the negative refractive power gradually becomes stronger during zooming. A predetermined zoom ratio is efficiently achieved with a small amount of movement. The compact zoom lens which is the object of the present invention can be achieved by satisfying the above conditions, but it is more preferable to set the above conditions as follows. In the above-mentioned imaging action, if the lateral magnifications at the wide-angle end and the telephoto end are respectively β 2W and β 2T for the second lens group, and β 3W and β 3T for the third lens group, then 1.0<β 2T /β 2W <1.5... (1) 1.0< β3T / β3W <1.7…(2) It is to be set within the range. This results in 3
A predetermined zoom ratio can be obtained in a well-balanced manner while reducing aberration fluctuations due to zooming of the two lens groups. If the upper limits of conditional expressions (1) and (2) are exceeded, the zoom ratio becomes too large, the refractive power of each lens group becomes excessive, or the amount of movement of the lens groups becomes excessive, making it difficult to reduce aberration fluctuations due to zooming. becomes difficult. Furthermore, it is optically very difficult to construct a zoom lens that exceeds the lower limits of conditional expressions (1) and (2). In particular, the multiplication ratio is so small that it takes 2
It becomes difficult to move two lens groups. Furthermore, in the present invention, under the conditional expressions (1) and (2), the composite refractive powers of the second lens group and the third lens group at the wide-angle end and telephoto end zoom positions are respectively 23W and 23T .
When 1.2< 23T / 23W <4.0...it is preferable to set it within the range of (3). With such a refractive power arrangement, a predetermined variable power ratio can be easily obtained without increasing the amount of movement of the third lens group. This is because the focal lengths of the second and third lens groups are f 2 and f 3 respectively, the distance between the principal points of the second and third lens groups is e 2 , and the composition of the second and third lens groups is If the refractive power is 23 , it can be expressed as 23 = 1/f 2 + 1/f 3 −e 2 /f 2 f 3 (a). Here, in the above formula (a), 1/f 2 >0, 1/f 3 <0, so 1/f 2 +1/f 3 <0
By setting the focal length of each lens group so that e 2 becomes smaller when changing the zoom position from the wide-angle end to the telephoto end, that is, by moving the third lens group toward the object side, the refractive power 23 is gradually increased. This is because it can be made stronger in the negative direction. Therefore, the refractive power 23 at the telephoto end zoom position can be maximized in the negative direction, and as a result, a high zoom ratio can be easily obtained by slightly moving the third lens group. . As explained above, the object of the present invention can be satisfactorily achieved by selecting the configuration of each lens group, but in order to achieve even better aberration correction over the entire zoom range and to reduce the size of the zoom lens, the following steps are required: It is preferable to satisfy the following conditions. The focal lengths of the first and third lens groups are f 1 and
f 3 , the focal length of the entire system at the wide-angle end zoom position is f W , the distance between the principal points of the first lens group and the second lens group at the wide-angle end zoom position is e 12W , and at the telephoto end zoom position When the principal point distance between the second lens group and the third lens group is e 23T , 0.3f W <f 1 <5f W ...(4) −2.5f W <f 3 <−0.5f W ……(5) e 12W >−0.5f W ……(6) e 23T >−0.4f W ……(7) The following conditions are satisfied. Conditional expression (4) relates to the refractive power of the first lens group, and when the lower limit is exceeded, the refractive powers of the second and third lens groups must have large negative values, especially at the telephoto end, in order to obtain a variable magnification ratio. Therefore, the Petzval sum increases in the negative direction and the curvature of field becomes excessive. On the other hand, if the upper limit is exceeded, not only will the contribution of zooming to the first lens group become smaller, but the lateral magnification β3 of the third lens group will have to be reduced, and the negative refractive power of the third lens group will be reduced. It has to be made smaller. As a result, the amount of movement of the third lens group increases, and the overall length of the lens increases, which is not appropriate. Conditional expression (5) relates to the refractive power of the third lens group, and when the upper limit is exceeded, the negative refractive power becomes large and the Petzval sum increases in the negative direction, so the curvature of field increases in the positive direction. If the lower limit is exceeded, the combined refractive power with the second lens group approaches the positive direction, so as mentioned above, a high zoom ratio cannot be obtained by slightly moving the third lens group, and a large amount of movement is required. Become. Also, if you exceed the lower limit and try to maintain the composite refractive power in the negative direction to obtain a predetermined zoom ratio, then according to equation (a) above, the second
The positive refractive power of the lens group becomes weak, and it is necessary to reduce the principal point distance e 2 between the second lens group and the third lens group, which is not appropriate because the movement space for the third lens cannot be obtained. Conditional expressions (6) and (7) are intended to shorten the overall length of the lens by appropriately setting the distance between each lens group.
If the ranges of (6) and (7) are exceeded, the distance between the lens groups at the wide-angle end and the telephoto end becomes too narrow, causing interference between the lens groups, which is undesirable in terms of lens construction. In the present invention, the focal length f 2 of the second lens group, which is fixed during zooming, is set as 0.5f W < f 2 < 6f W (8). This is preferable for promoting the magnification change effect caused by the movement of the lens and also for satisfactorily correcting aberrations of the entire screen during magnification change. If the upper limit of conditional expression (8) is exceeded, the refractive power of the second lens group becomes weaker, and when trying to obtain a predetermined variable power ratio, the second lens group, the third lens group It is necessary to take a large principal point interval e 2 , and the third
The negative refractive power of the lens group also becomes weaker and the amount of movement becomes larger. If the lower limit is exceeded, the refractive power of the second lens group becomes strong, the negative refractive power of the third lens group becomes excessive, and the distance between the principal points of the second lens group and the third lens group becomes small, resulting in a narrow movement space. It's gone and it's not appropriate. In a zoom lens in which the third lens group moves during zooming as in the present invention, the third lens group is composed of a meniscus-shaped lens with a negative refractive power with a convex surface facing the image surface side, over the entire zooming range. This is preferable for favorably correcting the image plane characteristics of the entire screen. In addition, in a zoom lens in which the first and third lens groups move during zooming as in the present invention, in order to reduce aberration fluctuations due to zooming and to satisfactorily correct various aberrations over the entire screen, it is necessary to The radius of curvature of the first lens surface on the object side of the lens group is R 11 ,
When R 31 , it is preferable to satisfy the following conditions: 0.5f W <R 11 <f W (9) −0.6f W <R 31 <−0.2f W (10). conditional expression
(9) and (10) are intended to satisfactorily correct the spherical aberration caused by zooming and the curvature of field of the entire screen.If the upper limit of conditional expression (9) and the lower limit of conditional expression (10) are exceeded, spherical aberration occurs. becomes over-corrected, and the curvature of field on the wide-angle side increases in the negative direction. Exceeding the lower limit of conditional expression 9 and the upper limit of conditional expression (10) is not preferable because spherical aberration will be insufficiently corrected and field curvature will increase in the positive direction. In the present invention, it is preferable to make the object-side lens surface of the third lens group an aspherical surface in order to achieve better aberration correction and obtain high-performance optical performance. In the present invention, focusing is preferably performed by extending the entire lens system, but it may also be done by extending the first lens group or the second lens group, or by retracting the third lens group. The second lens group may be extended integrally. As described above, according to the present invention, it is possible to achieve a compact zoom lens that is mechanically simple and has high zooming efficiency. Next, numerical examples of the present invention will be shown. In the numerical examples, R i is the radius of curvature of the i-th lens surface in order from the object side, D i is the thickness and air gap of the i-th lens surface in order from the object side, and N i and ν i are the radius of curvature of the i-th lens surface in order from the object side. These are the refractive index and Atpe number of the glass of the i-th lens. The aspherical shape has the X-axis in the optical axis direction, the Y-axis in the direction perpendicular to the optical axis, the direction of light travel as positive, the intersection of the vertex of the lens and the X-axis as the origin, and R as the paraxial curvature of the lens surface. Radius, a 1 , a 2 , a 3 , a 4 , a 5 , b 1 , b 2 , b 3 , b 4
When is the aspheric coefficient It is expressed by the following formula. For example, the display "D-03" means "10 -3 ".
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】【table】
第1図は従来の2群ズームレンズの光学系の概
略図、第2図は本発明の一実施例の光学系の概略
図、第3図A、Bは各々本発明の数値実施例1の
レンズ断面図と諸収差図、第4図A、Bは各々本
発明の数値実施例2のレンズ断面図と諸収差図、
第5図A、Bは各々本発明の数値実施例3のレン
ズ断面図と諸収差図、第6図A、Bは各々本発明
の数値実施例4のレンズ断面図と諸収差図、第7
図A、Bは各々本発明の数値実施例5のレンズ断
面図と諸収差図、第8図A、Bは各々本発明の数
値実施例6のレンズ断面図と諸収差図、第9図
A、Bは各々本発明の数値実施例7のレンズ断面
図と諸収差図である。
図中S,Cは正弦条件、△Sはサジタル像画、
△Mはメリデイオナル像面である。
FIG. 1 is a schematic diagram of an optical system of a conventional two-group zoom lens, FIG. 2 is a schematic diagram of an optical system of an embodiment of the present invention, and FIGS. 3A and B are each a diagram of a numerical embodiment 1 of the present invention. Lens sectional view and various aberration diagrams, FIGS. 4A and 4B are respectively a lens sectional view and various aberration diagrams of Numerical Example 2 of the present invention,
5A and 5B are respectively a lens cross-sectional view and various aberration diagrams of Numerical Example 3 of the present invention, FIGS. 6A and B are lens cross-sectional views and various aberration diagrams of Numerical Example 4 of the present invention, and FIG.
Figures A and B are a lens cross-sectional view and various aberration diagrams of Numerical Example 5 of the present invention, respectively. Figures 8A and B are lens cross-sectional views and various aberration diagrams of Numerical Example 6 of the present invention, respectively, and Figure 9A. , B are a lens sectional view and various aberration diagrams of Numerical Example 7 of the present invention, respectively. In the figure, S and C are sine conditions, △S is a sagittal image,
ΔM is the meridional image plane.
Claims (1)
第1、第2、第3レンズ群の3つのレンズ群を有
し、前記第2レンズ群を固定させ、前記第1レン
ズ群と、前記第3レンズ群を物体側へ移動させる
ことにより、広角端より望遠端のズーム位置への
変倍を行う際、前記第2レンズ群と前記第3レン
ズ群が共に増倍となるように変化させると共に、
前記第2レンズ群と前記第3レンズ群の合成屈折
力を広角端より望遠端への変倍に際し、負の方向
に序々に強くなるように各レンズ群を構成したこ
とを特徴とする小型のズームレンズ。 2 前記第1、第3レンズ群の焦点距離を各々
f1,f3、広角端のズーム位置における全系の焦点
距離をfW、広角端のズーム位置での前記第1レン
ズ群と前記第2レンズ群の主点間隔をe12W、望遠
端のズーム位置での前記第2レンズ群と前記第3
レンズ群の主点間隔をe23Tとするとき 0.3fW<f1<5fW −2.5fW<f3<−0.5fW e12W>−0.5fW e23T>−0.4fW なる条件式を満足することを特徴とする特許請求
の範囲第1項記載の小型のズームレンズ。[Claims] 1. It has three lens groups, first, second, and third lens groups having positive, positive, and negative refractive powers in order from the object side, and the second lens group is fixed, and the By moving the first lens group and the third lens group toward the object side, both the second lens group and the third lens group increase when zooming from the wide-angle end to the telephoto end. As well as changing it so that it doubles,
Each lens group is configured such that the combined refractive power of the second lens group and the third lens group gradually becomes stronger in the negative direction when zooming from the wide-angle end to the telephoto end. zoom lens. 2 The focal lengths of the first and third lens groups are respectively
f 1 , f 3 , f W is the focal length of the entire system at the zoom position at the wide-angle end, e 12W is the distance between the principal points of the first lens group and the second lens group at the zoom position at the wide-angle end, and e 12W is the focal length of the entire system at the zoom position at the wide-angle end. The second lens group and the third lens group at the zoom position
When the distance between the principal points of the lens group is e 23T , the conditional expression is 0.3f W < f 1 < 5f W −2.5f W < f 3 < −0.5f W e 12W > −0.5f W e 23T > −0.4f W A compact zoom lens according to claim 1, which satisfies the following.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59119474A JPS60263113A (en) | 1984-06-11 | 1984-06-11 | Small-sized zoom lens |
US06/741,634 US4726668A (en) | 1984-06-11 | 1985-06-05 | Zoom lens of short total length |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59119474A JPS60263113A (en) | 1984-06-11 | 1984-06-11 | Small-sized zoom lens |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS60263113A JPS60263113A (en) | 1985-12-26 |
JPS6361641B2 true JPS6361641B2 (en) | 1988-11-29 |
Family
ID=14762199
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP59119474A Granted JPS60263113A (en) | 1984-06-11 | 1984-06-11 | Small-sized zoom lens |
Country Status (2)
Country | Link |
---|---|
US (1) | US4726668A (en) |
JP (1) | JPS60263113A (en) |
Families Citing this family (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6317422A (en) * | 1986-07-09 | 1988-01-25 | Canon Inc | Small-sized variable power optical system |
JPH083580B2 (en) * | 1986-12-18 | 1996-01-17 | オリンパス光学工業株式会社 | Compact high-magnification zoom lens |
US4854682A (en) * | 1987-11-13 | 1989-08-08 | Olympus Optical Co., Ltd. | Compact high vari-focal ratio zoom lens system |
JP2798090B2 (en) * | 1988-02-10 | 1998-09-17 | オリンパス光学工業株式会社 | Focusing method of zoom lens |
JPH0331809A (en) * | 1989-06-29 | 1991-02-12 | Olympus Optical Co Ltd | Zoom lens |
US5327290A (en) * | 1989-10-13 | 1994-07-05 | Minolta Camera Kabushiki Kaisha | Compact size zoom lens system |
US5283693A (en) * | 1990-06-13 | 1994-02-01 | Minolta Camera Kabushiki Kaisha | Compact zoom lens system |
US5225941A (en) * | 1990-07-03 | 1993-07-06 | Canon Kabushiki Kaisha | Driving device |
JPH0467114A (en) * | 1990-07-09 | 1992-03-03 | Olympus Optical Co Ltd | Variable power lens |
JP3009052B2 (en) * | 1990-07-18 | 2000-02-14 | オリンパス光学工業株式会社 | Small three-group zoom lens |
US5424870A (en) * | 1990-07-20 | 1995-06-13 | Minolta Camera Kabushiki Kaisha | Compact zoom lens system |
JP3060117B2 (en) * | 1990-12-26 | 2000-07-10 | オリンパス光学工業株式会社 | Compact 3-group zoom lens |
JP3060557B2 (en) * | 1991-02-15 | 2000-07-10 | オリンパス光学工業株式会社 | Compact 3-group zoom lens |
US5353160A (en) * | 1991-07-24 | 1994-10-04 | Olympus Optical Co., Ltd. | Three-unit compact zoom lens system |
US5815320A (en) * | 1993-01-14 | 1998-09-29 | Canon Kabushiki Kaisha | Zoom lens |
JPH07199070A (en) * | 1993-12-28 | 1995-08-04 | Nikon Corp | Zoom lens |
US5726810A (en) * | 1996-06-21 | 1998-03-10 | Eastman Kodak Company | Compact zoom lens |
US5825556A (en) * | 1996-09-30 | 1998-10-20 | Eastman Kodak Company | Zoom lens |
US5886829A (en) * | 1997-07-28 | 1999-03-23 | Eastman Kodak Company | Compact zoom lens with a large zoom ratio |
US5999330A (en) * | 1998-12-03 | 1999-12-07 | Eastman Kodak Company | Zoom lens |
JP5963039B2 (en) * | 2012-03-16 | 2016-08-03 | 株式会社リコー | Imaging lens, camera and portable information terminal device |
US10495852B2 (en) * | 2018-02-11 | 2019-12-03 | AAC Technologies Pte. Ltd. | Camera optical lens |
CN108562998B (en) * | 2018-02-11 | 2020-10-23 | 瑞声光学解决方案私人有限公司 | Image pickup optical lens |
US10551592B2 (en) * | 2018-02-11 | 2020-02-04 | AAC Technologies Pte. Ltd. | Camera optical lens |
US10712534B2 (en) * | 2018-02-11 | 2020-07-14 | Aac Optics Solutions Pte. Ltd. | Camera optical lens |
US10795124B2 (en) * | 2018-02-11 | 2020-10-06 | Aac Optics Solutions Pte. Ltd. | Camera optical lens |
JP6518364B1 (en) * | 2018-04-26 | 2019-05-22 | エーエーシー テクノロジーズ ピーティーイー リミテッド | Imaging optical lens |
JP6523529B1 (en) * | 2018-04-26 | 2019-06-05 | エーエーシー テクノロジーズ ピーティーイー リミテッド | Imaging optical lens |
TWI703364B (en) | 2019-11-29 | 2020-09-01 | 大立光電股份有限公司 | Photographing optical lens assembly and electronic device |
CN111158114B (en) * | 2020-02-24 | 2022-01-07 | 诚瑞光学(常州)股份有限公司 | Image pickup optical lens |
CN111929827B (en) * | 2020-09-03 | 2021-04-30 | 诚瑞光学(苏州)有限公司 | Image pickup optical lens |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56128911A (en) * | 1980-03-14 | 1981-10-08 | Canon Inc | Subminiature zoom lens |
JPS57201213A (en) * | 1981-06-04 | 1982-12-09 | Canon Inc | Microminiature zoom lens |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4494828A (en) * | 1981-04-09 | 1985-01-22 | Minolta Camera Kabushiki Kaisha | Zoom lens system of relatively high zoom ratio ranging to wide angle photography |
JPS5888717A (en) * | 1981-11-24 | 1983-05-26 | Olympus Optical Co Ltd | Zoom lens |
-
1984
- 1984-06-11 JP JP59119474A patent/JPS60263113A/en active Granted
-
1985
- 1985-06-05 US US06/741,634 patent/US4726668A/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56128911A (en) * | 1980-03-14 | 1981-10-08 | Canon Inc | Subminiature zoom lens |
JPS57201213A (en) * | 1981-06-04 | 1982-12-09 | Canon Inc | Microminiature zoom lens |
Also Published As
Publication number | Publication date |
---|---|
US4726668A (en) | 1988-02-23 |
JPS60263113A (en) | 1985-12-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JPS6361641B2 (en) | ||
JP3478637B2 (en) | Small zoom lens | |
JP4478247B2 (en) | Zoom lens | |
JPH0354325B2 (en) | ||
US7457049B2 (en) | High magnification zoom lens | |
JPH083580B2 (en) | Compact high-magnification zoom lens | |
JPH05173071A (en) | Wide angle zoom lens | |
JPH075361A (en) | Zoom lens | |
JP5528211B2 (en) | Zoom lens and imaging apparatus having the same | |
JP2000009997A (en) | Zoom lens | |
JPH08304703A (en) | Compact zoom lens | |
JP3849129B2 (en) | Zoom lens | |
JP2000330016A (en) | Zoom lens | |
JPH0642017B2 (en) | Compact zoom lens | |
JP4391639B2 (en) | High magnification zoom lens | |
JP3184581B2 (en) | Zoom lens | |
JP2005134746A (en) | Zoom lens and imaging unit having the same | |
JPH095626A (en) | Variable power optical system | |
JP2722709B2 (en) | Zoom lens | |
JP2546293B2 (en) | Small zoom lens | |
JP2006003539A (en) | Zoom lens and imaging apparatus having same | |
JP3219574B2 (en) | Zoom lens | |
JPH08110470A (en) | Wide angle zoom lens | |
JP3593400B2 (en) | Rear focus zoom lens | |
JP2004264457A (en) | Super-high magnifying zoom lens |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EXPY | Cancellation because of completion of term |